MOE: Margin of Exposure: First the average human daily intake of
rodent carcinogen is divided by 70 kg body weight to give estimated
human intake in mg/kg/day. Second, LTD10 is calculated
from the Carcinogenic Potency Database as the lower 95% confidence
limit on the tumorigenic dose-rate for 10% of rodents (mg/kg/day).
Third, MOE is calculated as

The example below is for the naturally-occurring chemical
acrylamide, which is formed by cooking starch-rich foods at high
temperature. In the graphic and the table, the MOE is reported for
the total intake of acrylamide in the average US diet and also for
consumption of just French fried potatoes in restaurants.

MOE (LTD10/Human Exposure)

Average Daily US Exposure

Human Intake of Rodent Carcinogen
Amount per Day [Amount in mg/kg/day]

Rodent Cancer Dose LTD10
[mg/kg/day]

References for Human Exposure

Rats

Mice

900

Acrylamide in total diet

Acrylamide, 28 µg [0.0004 mg/kg/day]

0.365

.

(DiNovi and Howard 2004)

6,000

French fries (restaurant), 12.2 g

Acrylamide, 4.06 µg [0.000058
mg/kg/day]

0.365

.

(DiNovi and Howard 2004)

For Acrylamide in the total diet:

Human Exposure for Acrylamide in total diet = 28 µg/day
expressed as 0.0004 mg/kg/day (28 µg daily intake / 70 kg
human). Consumption of acrylamide in the total diet is reported in
the reference in the table above.

LTD10: the chronic dose-rate in mg/kg body
weight/day which would induce tumors in 10% of test animals = 0.365
mg/kg/day for rats. The LTD10 values used in MOE are
averages for rats and mice separately, calculated by taking the
harmonic mean of the LTD10 values from
positive experiments. For acrylamide the only experiments in the
Carcinogenic Potency Database are in rats, indicated by
“.” for mice in the table. The LTD10 in rats
is 0.365 mg/kg/day, which is a harmonic mean of the most potent
values from several positive experiments in rats in the CPDB.

Both the average concentration of acrylamide in restaurant
French fries (333 µg/kg = 0.333 ppm) and the average US
consumption of French fries in restaurants (12.2 gm/day) are
used, and are from the reference.

The consumption of acrylamide in French fries in mg/day is as
follows:

Consumption of French fries in restaurants averages 12.2 g/day
(column 1 of table). From the concentration of acrylamide in French
fries, the amount consumed in 12.2 g is calculated as 4.06 µg
[0.00406 mg]. This amount is calculated as 0.000058 mg/kg/day for a
70 kg person.

LTD10: the chronic dose-rate in mg/kg body
weight/day which would induce tumors in 10% of test animals = 0.365
mg/kg/day for rats.